Knob-insulator.



GUSTAVE GLOCKER, OF NORTH EAST, MARYLAND.

KnoB-msuLAToR.

Specification of Letters Patent.

Patented J an. 7, 1919.

Application led March 6, 1918. Serial No. 220,773.

To all rwhom it may concern:

Be it known that I, GUsrAvE Gnooxnn, a citizen of the United States, residin at yNorth East, in the county of Ceciland tate of Maryland, have invented a new and useful Knob-, Insulator,` of which the following is a s ecification i his invention has reference tn electric insulators of the knob and )cap type, which insulators are customarily" made of porcelain, and its object is to provide an insulator permitting the cap and khob -tofbe fired at `the same time, with the c in place on the knob, and also to provid'e' or the clamping of theelectric conductor":moreJ Asecurely than heretofore. i v

In accordance with the invention, the in'- sulato'r hasthe `body portion provided withconductor-'eceiving channels on opposite sides of a dlametric, web, with the channels ribbed or roughened to hold the insulated conductor a-galnst slipping, the cap having a central Vboss or projection of a size to override the channels, and therebyl provide .clam ing meansfor the electric'conductors, while the central rib of the body portion of :the knob is recessed to receive the boss, thus holding the cap against displacement. That lend of the body orbase portion of the knob :opposite from the cap receiving end is veountersunk and provided with an axial projection within the countersink extended close to but stopping short of the corresp'onding end of the knob base. The projection serves tocarry the cap by the central boss of the latter on introducing the coated knobs and caps in the furnace for ring them. These features render the insulator,

4both in the matter of manufacture and use,

advantageous over similar insulators as heretofore made. f The invention will be best understood -fr'om aconsideration of the following de tailed description, taken in connection with the accompanying drawing forming part of this specification, with the further understanding that, while the drawing shows a practical form of the invention, the latter is not confined to any strict conformity with the showing oi' the drawing but may be changed and modified so long as such changes and modifications come within the scope of the ap ended claims.

In t e drawing Figure 1 is an elevation of the insulator knob and cap;

Fig. 2 is a central diametro section cut-- tirg across the conductor-receiving chai ne s; 'I

Fig 3 is a section on the line 3-3 of Fig. l;

Fig. 4 is a view of the conductor-engaging face of the cap; Fig. 5 is a view of the conductor-engaginvface 0l the body of the knob.

1g. 6 1s a longitudinal lsection of the knob base and cap as associated for firing.

Referring to the drawings, there is Ashown a knob comprising a body member 1 and a cap 2, such knob being custgrlnarily of cylin drical conformation, and is ade of earthenware material, ordnaril known as porcelain, and has the expose surface glazed.

The bod memberor base 1 and the cap 2 are forme( with central longitudinal mateh ing channels 3 and 4 res ectively, with the channel 4 at that facon? from the body member 1 countersunk, as shown at 5, so that a screw `or nail may be utilized for fastening the insulator knob in that the terminal portions of the rib or web' 7 are on the same level as the remainder of the corresponding end ofthe body portion I, such end bein substantially 'lat. Be-

tween the outer sides of the grooves 6 and.

the margins oi the body member 1, are ledges 9'in the same plane as the ends of the rib 7.

The grooves 6 have each a series -of latorally disposed projections 10- forming teeth or gripping means for engaging the insulation covering of the conductor lodged 1n the groove, and so prevent slipping of the' the cap 2 remote B Je conductor without necessitating excessive pressure in clamping thtI conductor.

The cap 2 is in the forni of' :i cylindrical block, with that ture designed to engage the body member 1 provided with n circular flut boss 11, with the face remote from the cap having an annular series of teeth or projections 12, radiating `from il ring 13 surrounding the passage 4. The projections 1:2, like the teeth or projections l() in the grooves G, extend iiwny from the cup only sufficiently to forni u roughencd or gripping surface to engage the insulation coveringr the co1iductor sented in n groove 6 to hold the latter against slipping through the insulator, without, however, any injury to the insulation.

The depression 8 in the rib is of n length but 'little longer lhini the diameter of the boss 11. The boss 11 not only serves as an anchor to hold the cup on the body portion against displacement by forces incident to handling the knob structure when being placed .into iin oven to tireyit, as will hereinafter appear, but the boss serves iis e clamping member for the conductor or cond uctors lodged in the groove or grooves 6. In order to avoid any stier points at the ends of the grooves 6, said ent s of the grooves are expanded, iis indicated in the drawings.

At that end of the basic portion of tlie knob remote from the one designed to re ceive the cap 2 is :i eountersink 14 within which there is produced iin axial projection 15 extending close to but not reaching the outer'end of the countersink 14. The

length of the projection 15 is such thnt when the parts are first molded and before firing, the boss 11 will enter the countersink 14 and rest upon the projection 15 with the boss )arti within the countersink 14.

W ien tie knobs are place-d in the furnace forf firing, theciips 2 rest upon the projections 15, the biisic portions of the knobs being at the time inverted, with the rojections 15 uppermost. The support tor the caps 2 is relatively Iiilge, und the bosses 11V project sufiiciently into the countersinks 14 'to avoid liability of the caps being displaced in handling. t the saune time, the caps are raised sufficiently above the knob bases to avoid :my danger of the glazing iniiteriiil of, the cups and knob buses `uniting and so cementing the piiitstogcther. The result is that breakage or injury to the knobs during the firing operation is greatly reduced and practically eliminated.

The construction of the knob isndvnn'-` tngeous iii permitting the firingof the oeps zuid baises together with little or no liability of injury beciiuse of thebrozid support of the cap on tlie'pi'ojcctioii 15 during lirin i'nillivlinnztlio' pdr-tsk nre ip'rticu'lnrlvli-.mb er projecting from the face designed to engage theA grooved end of the body member, the boss being of cylindrical shape, and of a diameter to enter the recess in the rib and extend across the grooves on opposite sides of the rib.

2. An insulator knob for electric conductors comprising a body member having a, diametric rib across one end with conductorreceiving grooves flanking said rib, and the rib being recessed lengthwise, and acap for the grooved end of the body member, said cap having an intermediate flat bosspro- Jecting from the face desi ed to engage the groovcd end of the bodv member, the boss being of cylindrical shape, and of a. diameter to enter the recess in `the rib and extend across the grooves on opposite sides of the rib, both the grooves and the boss having shallow teeth or projections for engaging a conductor or conductors lodged in the groove or grooves 3. An insulator knob for electric conductors comprising a body member having a diametric rib across.` one end withconductorreceiving grooves anking sid rib, Vand the rib.bei`ng recessed lengthwise, and a. cap for the 1grooved end of t e bod cop aving an intermediate atboss projecting from the face desi grooved end of the bo member, the. boss being of cylindrical shape and of a. diameter to enter the recess in t e rib iind extend across the rooves on op osite sides of the rib, both t e grooves an y shallow teeth or projections for engaginga conductor or oonductorslodged ,in ythe groove .or grooves, and theyteeth or projections in the grooves extendingptrsnsxersely of the length of the lettori. with thai or projections in the boss arrangedflrqdially thereof in circular series.

4. An insulator knob for electricA tors comprising a body member counters'uiik'.

axial extension stopping [s y end of the body membenendriiggep member with :in axial fiat boss of greater axial'len l1 than the free end of the projection wit in um .cmilsipk and the corresponding end member, said at the basic end and ,there Erovidadt,hvvitllif'on.` ort o e asie of the body member, whereby the body member :and f'np member muy he fired together, with the cup member sustained by the projection ofthe body men'xber, :md the boss 0f the cup member entering the eountersink in the bod)y member to an extent less than the axial length of the boss.

In testimony, that I eblim the foregoing as my own, I have hereunto axed my signature in the presence of witnesses.

GUSTAVE GLUUKER. Witnesses:

F. H. THOMPSON,

IHAS. A. STEWART. GAmm'rr F. HAMmrloN. WILLIAM J. LOGAN. 

